In conventional electronic equipment, such as cellular phones and household appliances, piezoelectric sounding components that produce warning sounds and operation sounds, such as piezoelectric speakers and piezoelectric sounders, are widely used.
For example, Japanese Unexamined Patent Application Publication No. 2004-15767 discloses such a piezoelectric sounding component. The piezoelectric sounding component described therein has a structure where a piezoelectric sounding body (diaphragm) constituted of a piezoelectric element, which is ceramic for example, and a metal plate, is accommodated in a casing. The diaphragm accommodated in the casing is fixed to the casing with an elastic adhesive. Further, a conductive adhesive, electrically connected to the piezoelectric element, is formed on top of the elastic adhesive on sides of the diaphragm which face each other.
In the foregoing piezoelectric sounding component the casing is formed so as to be larger than the diaphragm in terms of accommodation and thus a gap is formed between the inside edge of the casing and the peripheral outside edge of the diaphragm. Conductive adhesives are formed on opposing sides of the diaphragm. When the diaphragm is arranged so that the diaphragm is closer to one side of the casing than the other, one of the conductive adhesives needs to be longer than the other. As a result, the longer conductive adhesive receives increased stress applied through the vibration of the diaphragm. Thus, the conductive adhesive can break and is susceptible to improvement in terms of reliability.
The present invention has been made in view of such circumstances and is aimed at providing a piezoelectric sounding component with high reliability.